It appears that Americans don't wash their bed sheets as often as they should. Website Mattress Advisor asked 1,000 people how often they wash their sheets and pillow cases and discovered most go at least a month or so without changing them.

Even if you eat kale and exercise and somehow resist the office cupcakes, it won't matter much if you don't get a decent amount of sleep. Your body and mind desperately needs rest to function properly.

If only it were as easy as shutting your eyes. Take a look at your sleep habits to find out whether you're making these major mistakes, and learn how to fix them so you can optimize your sleep:

1. You swear by your sleep tracker.

"You don't need a health tracker to find out if you've had a good night sleep," says Matt Leve, physical therapist at Shift Integrative Medicine in New York City. You know that feeling you get when you wake up on vacation? It's called refreshed, and it's how you should feel every. Single. Day. The American Academy of Sleep Medicine (AASM) recommends adults get about seven to nine hours of quality nightly sleep for optimal health, productivity, and daytime alertness. Even if your tracker says you've slept enough, if you generally wake up groggy, absolutely require caffeine to function, or doze off throughout the day, you're not getting adequate sleep.

Even if you eat kale and exercise and somehow resist the office cupcakes, it won't matter much if you don't get a decent amount of sleep. Your body and mind desperately needs rest to function properly.

If you sleep on your back, wedge one under your knees to take pressure off your lower back. Or if you sleep on your side, wedge a pillow underneath your top armpit to support your arm and one between your legs to keep your spine aligned.

Sleeping facedown can cause
some obvious issues — like not being able to breathe, for example.
Because you need to turn your head to one side to get air in and out,
you inherently twist your spine. Over time, this can cause neck and back
pain (not to mention issues falling and staying asleep), says Ilene
Rosen, M.D., an associate professor of clinical medicine for the
University of Pennsylvania School of Medicine in Philadelphia and member
of the board of directors for the AASM. To straighten your spine, bend
the elbow and knee on the side you typically turn your head toward, and
wedge a pillow underneath that armpit and hip. If you tend to kick the
pillows and wake up flat on your stomach, tape a tennis ball to the
front of your pajama shirt to teach your sleeping self not to roll. And
if you really can't sleep in a modified position? Wedge a thin pillow
under your abdomen to take pressure off your back.

While drinking at
night can help you doze off at first, it can also cause you to wake up
throughout the night, which will ultimately interfere with the quality
of your sleep, according to a comprehensive review
of existing research that was published last year. The more you drink,
the worse you're going to sleep. If you plan to throw back more than a
few stiff ones, start early and slow down toward the end of the night.

When you crash hard at 9
p.m. on Monday night and stay up all night Tuesday to binge-watch your
Netflix queue, your body won't know when to shut down on Wednesday
night. A consistent sleep schedule helps your body know when it's time
to fall asleep and wake up, Leve says. Read: It makes mornings less
painful.

Think you can run on no
sleep all week and catch up Saturday morning? Leve says it doesn't work
like that. Recent research suggests skimping on sleep can actually lead
to permanent brain damage that can compromise your alertness and brain
power — and binge-sleeping can't mend that.

Whenever you eat
dinner less than three hours before bedtime, you put yourself at risk
for heartburn and indigestion, which can make it tough to doze off,
according to research
published in the American Journal of Gastroenterology. Keep late-night
snacks light, and always avoid fatty, fried, or spicy foods before bed.

They're amazing
for pillow fights but awful for back sleepers. Ideally, your pillow
should elevate your head and neck just enough to keep your spine
straight while you sleep. Pillows that raise your head more than a few
inches cause you to round your head and shoulders forward. You can get
away with a slightly higher pillow when you sleep on your side, because
there's more room to fill between the side of your head and the mattress
when you lie in that position.

At the end of the day, the best
pillow will be the one with the best return policy. It's almost
impossible to tell whether a pillow will be comfortable before you take
it home — even if you test it on a bed in the store, the softness of
your own mattress will affect how your body relates to the pillow. When
you do take it home, ask your partner or roommate to look at you and
touch along your spine. If it's not straight when you lie on the pillow
in your typical position? Next! Any spinal curves will ultimately
compress the discs in your spine or pinch the nerves, and result in
pain.

This side-sleeper
tendency can restrict your breath and compromise the quality of your
sleep, Leve says. Wedge a body pillow under your top arm and leg to
unwind your limbs and lengthen your spine. Even if you kick it away at
some point during the night, you'll at least get some good quality
sleep. (Or rest assured that you tried.)

Most
inner spring mattresses only last for five or 10 years, max, depending
on the quality of your mattress, your weight, and how much time you
spend in bed. If yours has a large indentation in the middle, or your
body sags into the mattress when you lie on it, you'll likely wake up
with lower back, hip, or shoulder pain. A foam cover or a new mattress
can help.

That goes for both
lingerie and bedding: Foam mattresses, sateen sheets, and satin PJs may
feel good. But they retain body heat more than natural materials, which
can amount to a temperature change that wakes you up, Leve says. Always
sleep in sheets and pajamas made of cotton, bamboo, or natural fiber. If
you have a foam mattress, use a wool mattress topper that's at least a half an inch thick. It will wick away body moisture so you don't wake up with the sweats.

Sorry,
Goldilocks, there's no perfect mattress — it all depends on your frame
and weight and personal preference. That said, yours is probably too
soft if you feel like you sinking into it. If your pelvis drops more
than a few inches, you could suffer from lower back pain, Leve says.

If your body
doesn't sink at all, you could develop a curve in the spine that causes
a stiff back and shoulders or hip pain in the morning, Leve says. Buy a
foam mattress cover to make it a little more forgiving.

These
screens emit blue light that activates your brain and interferes with
your body's natural sleep cycle, Leve says. The phone thing is one of
the worst: If you get a text or email in the middle of the night — even
after you close your eyes — the light can go right through your eyelids
and stimulate your nervous system and brain. So you can kiss your deep,
restorative sleep good-bye. Ideally, leave your phone outside your room
while you sleep. If that's not an option, put it in silent mode with the
screen facing down on a surface that's far from your bed. As for TV?
Tune out an hour or two before bed to give your brain a chance to rest,
and when you say your prayers? Remember to thank DVR.

Light is a
product of modern civilization, and humans aren't designed to bask in
glaring streetlights while they sleep. "Try black out shades — they're
the best thing you can do for your brain," Leve says. A sleep mask can help too.

Temperatures above 75 degrees Fahrenheit and below 54 degrees will disrupt sleep, according to the National Sleep Foundation. Recent research suggests that sleeping in a room that's about 66 degrees can increase your metabolism. (Just sayin'.)

This stinks up your
sheets, and if you wear sandals or walk barefoot around the house, it
can redeposit the dirt and dust you picked up throughout the day onto
the bottom of your bed. (Gross.) A warm bath or shower will fix that.
Plus, it will raise your body temperature, so by the time you tuck in,
your temperature naturally will be dipping back down, which gets your
body into sleep mode so you fall asleep faster.

Sixty-three percent of pet owners who sleep beside their pets sleep poorly more often than not, according to research presented at a recent Annual Associated Professional Sleep Societies meeting. Hope Fido likes the floor.

Men on the whole don't change their sheets very often compared to women, by almost a ten percent margin. Couples either married or in a relationship kept on top of changing things up the most.

Single guys might wait up to 45 days before changing out their bedding. Guys, you can do better. Women for that matter, change their sheets about once a month.

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Fun gross fact: roughly 19 percent of people who sleep in the nude wait 20 days before changing the linen. No matter your opinion on sleeping in the nude, that is a gross percentage.

Speaking of nudity, guys reported waiting up to 11 days to change sheets after sexual activity compared to women who wait around 4 days. After a one-night performance, guys reported waiting 18 days, compared just two days for ladies.

According to Mattress Advisor, the average human leaves around 26 gallons of sweat into his or her sheets each year. We also drop about 10 grams of skin each day, with some going onto our beds that we spends hours laying in. Do the math, our beds are monuments to ick.

What's the issue here? Are we too busy to wash our sheets? Is it too much work to throw them in the washer? Clean sheets are a luxury in which more people should indulge.